1. Field
Embodiments relate to an apparatus and a method for imaging and measuring ganglion cells. More particularly, embodiments relate to an apparatus and a method for measuring ganglion cells capable of measuring number, density, etc. of ganglion cells in the retina of a human or animal eye and thus diagnosing presence and progress of diseases such as glaucoma.
2. Description of the Related Art
Glaucoma is an eye disease in which the function of the optic nerve is impaired as the optic nerve is pressed or the blood flow is restricted owing to raised intraocular pressure. The damage of the optic nerve leads to visual field loss, which over time can progress to blindness. Whereas acute glaucoma can be detected early due to severe pain, chronic glaucoma has few symptoms and, when symptoms are found, it is generally too late to treat. Accordingly, it is very important to detect glaucoma early through periodic examinations.
Since the major cause of glaucoma is damages to ganglion cells, the progress of glaucoma can be diagnosed by observing the degree of damage of the ganglion cells. The simplest method is to measure the intraocular pressure and, if it is higher than the normal intraocular pressure, treatment for glaucoma is made to lower the intraocular pressure below the normal level. For example, Korean Patent Application Publication No. 10-2011-0054584 discloses a device for measuring the intraocular pressure of a patient for diagnosis and treatment of glaucoma. However, the diagnosis based on the intraocular pressure measurement is not so accurate.
Recently, the optical coherence tomography (OCT) technique, whereby the thickness of the layer of the retina where ganglion cells are located is measured to diagnose the progress of glaucoma, is frequently used. In general, it is known that raised intraocular pressure leads to damage of the optic nerve since the optic nerve is pressed and, as a result, the ganglion cells connected to the optic nerve die and the thickness of the layer where the ganglion cells existed decreases. But, if the decreased thickness of the layer is measurable by OCT, glaucoma has already progressed a lot. Therefore, it is difficult to detect glaucoma at an early stage using this method.